Un-deprecate Parser.config and Parser.env

PRs #13644 and #13637 deprecated ``Parser.config``, ``Parser.env``, and
``Parser.set_application`` in 9.0, scheduled for removal in 10.0.
However, the registry already populates ``_config`` and ``_env`` directly
when constructing parser instances, and there is no documented public
replacement for the property accessors.  Third-party parsers such as
``sphinx_bib_domain`` rely on reading config/env during ``parse()``, and
projects using ``-W error`` in CI now fail outright on the deprecation
warnings.

Reverse the deprecation of ``Parser.config`` and ``Parser.env`` so that
they remain the supported way for parsers to access the build
configuration and environment.  ``Parser.set_application`` is kept
deprecated since the hook is genuinely redundant once ``_config`` and
``_env`` are set by the registry.

Document the supported access pattern in ``doc/extdev/parserapi.rst``
and add a regression test that asserts no ``RemovedInSphinx10Warning``
is emitted on attribute read.

Fixes #14371

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: FazeelUsmani

AUTHORS.rst

@@ -56,6 +56,7 @@ Contributors
 * Erik Bedard -- config options for :mod:`sphinx.ext.duration`
 * Etienne Desautels -- apidoc module
 * Ezio Melotti -- collapsible sidebar JavaScript
+* Fazeel Usmani -- parser API fixes
 * Filip Vavera -- napoleon todo directive
 * Florian Best -- log improvements
 * Glenn Matthews -- python domain signature improvements

CHANGES.rst

@@ -1,3 +1,14 @@
+Release 9.2.0 (in development)
+==============================
+
+Bugs fixed
+----------
+
+* #14371: Un-deprecate :py:attr:`!Parser.config` and :py:attr:`!Parser.env`,
+  the supported way for a custom parser to access the build configuration
+  and environment.  Only :py:meth:`!Parser.set_application` remains deprecated.
+  Patch by Fazeel Usmani
+
 Release 9.1.0 (released Dec 31, 2025)
 =====================================
 

doc/extdev/parserapi.rst

@@ -36,3 +36,33 @@ to configure their settings appropriately.
 
 .. autoclass:: Parser
    :members:
+
+Accessing the Sphinx config and environment
+-------------------------------------------
+
+A custom parser can read Sphinx :class:`~sphinx.config.Config` values and the
+:class:`~sphinx.environment.BuildEnvironment` through the inherited
+:attr:`Parser.config` and :attr:`Parser.env` properties.  Sphinx sets the
+backing ``_config`` and ``_env`` attributes when it constructs the parser via
+:meth:`.Sphinx.add_source_parser`, so they are available from the moment
+:meth:`Parser.parse` is called.
+
+.. code-block:: python
+
+   from sphinx.parsers import Parser
+
+
+   class MyParser(Parser):
+       supported = ('mytype',)
+
+       def parse(self, inputstring, document):
+           # ``self.config`` and ``self.env`` are populated by Sphinx
+           encoding = self.config.source_encoding
+           docname = self.env.docname
+           ...
+
+.. versionchanged:: 9.0
+   The :meth:`Parser.set_application` hook is deprecated.  Sphinx now sets
+   ``_config`` and ``_env`` directly when the parser instance is created, so
+   custom parsers no longer need to override ``set_application`` to capture
+   these objects.

sphinx/parsers.py

@@ -36,24 +36,33 @@ class Parser(docutils.parsers.Parser):
 
     @property
     def config(self) -> Config:
-        """The config object."""
-        cls_module = self.__class__.__module__
-        cls_name = self.__class__.__qualname__
-        _deprecation_warning(cls_module, f'{cls_name}.config', remove=(10, 0))
+        """The config object.
+
+        Sphinx sets this attribute when constructing the parser via
+        :meth:`.Sphinx.add_source_parser`, so it is available throughout
+        :meth:`parse`.
+        """
         return self._config
 
     @property
     def env(self) -> BuildEnvironment:
-        """The environment object."""
-        cls_module = self.__class__.__module__
-        cls_name = self.__class__.__qualname__
-        _deprecation_warning(cls_module, f'{cls_name}.env', remove=(10, 0))
+        """The environment object.
+
+        Sphinx sets this attribute when constructing the parser via
+        :meth:`.Sphinx.add_source_parser`, so it is available throughout
+        :meth:`parse`.
+        """
         return self._env
 
     def set_application(self, app: Sphinx) -> None:
         """set_application will be called from Sphinx to set app and other instance variables
 
         :param sphinx.application.Sphinx app: Sphinx application object
+
+        .. versionchanged:: 9.0
+           Deprecated.  Sphinx now sets :attr:`_config` and :attr:`_env`
+           directly when the parser is created, so this hook is no longer
+           needed.  It will be removed in Sphinx 10.
         """
         cls_module = self.__class__.__module__
         cls_name = self.__class__.__qualname__

tests/test_markup/test_parser.py

@@ -2,11 +2,13 @@
 
 from __future__ import annotations
 
+import warnings
 from typing import TYPE_CHECKING
 from unittest.mock import Mock, patch
 
 import pytest
 
+from sphinx.deprecation import RemovedInSphinx10Warning
 from sphinx.parsers import RSTParser
 from sphinx.util.docutils import new_document
 
@@ -68,3 +70,16 @@ def test_RSTParser_prolog_epilog(RSTStateMachine: Mock, app: SphinxTestApp) -> N
         ('dummy.rst', 0, '        hello Sphinx world'),
         ('dummy.rst', 1, '  Sphinx is a document generator'),
     ]
+
+
+@pytest.mark.sphinx('html', testroot='basic')
+def test_parser_config_env_not_deprecated(app: SphinxTestApp) -> None:
+    """Reading ``Parser.config`` / ``Parser.env`` must not warn (#14371)."""
+    parser = RSTParser()
+    parser._config = app.config
+    parser._env = app.env
+
+    with warnings.catch_warnings():
+        warnings.simplefilter('error', RemovedInSphinx10Warning)
+        assert parser.config is app.config
+        assert parser.env is app.env